1. Field of the Invention
The present invention generally relates to a motor winding structure and, more particularly, to a motor winding structure that allows a plurality of coils thereof to be electrically connected together without having to arrange any conducting hole on the base plate of the motor winding structure.
2. Description of the Related Art
FIG. 1 shows a conventional motor 8 including a base plate 81, a winding assembly 82 and a rotor 83. The winding assembly 82 is coupled with the base plate 81, and the rotor 83 is rotatably coupled with the base plate 81. The winding assembly 82 includes a board 821 and a plurality of coils 822 arranged on the board 821. The plurality of coils 822 is arranged on the board 821 by electroforming or layout. In this arrangement, the plurality of coils 822 is magnetically linked with the rotor 83, driving the rotor 83 to rotate. Such a motor can be seen in Taiwan Patent No. 1384723.
In the motor 8, the plurality of coils 822 must be electrically. connected to each other. Specifically, each coil 822 has a center “C” and includes two ends. Each coil 822 is formed on the board 821 and extends in a clockwise or counterclockwise manner. One of the two ends of the coil 822 is adjacent to the center “C,” and another end of the coil 822 is away from the center “C.” Since the coil 822 is formed on the board 821 by layout, the end of the coil 822 adjacent to the center “C” (innermost part of the coil 822) cannot extend across the loops of the coil 822 to connect to the other coil 822 or an external power. In light of this, it is required to arrange a conducting hole that extends through the board 821 at the center “C” of the coil 822. Then, a conducting element such as a copper post, a conducting wire or a conducting layer is disposed in the conducting hole, such that the innermost part of the coil 822 can be connected to the other coil 822 or the external power via the conducting element. Alternatively, the innermost parts of the plurality of coils 822 can also be connected to each other via a jumper or jumpers.
However, arrangement of the conducting hole and the conducting element increases the manufacturing cost and structural complexity of the motor 8. Although the jumpers are used to connect the plurality of coils 822 together, the production of the motor 8 is difficult in order to prevent the jumpers from making contact with the electronic components of the board 821. Furthermore, arrangement of the jumpers increases the thickness of the board 821, which is against the purpose of miniaturization as required by the motor 8.
FIG. 2 shows another conventional motor winding structure 9 including a flexible base plate 91 and a winding assembly 92. The flexible base plate 91 includes a plurality of boards 911 and a plurality of bridges 912. Each bridge 912 is connected between two adjacent boards 911. The winding assembly 92 includes a plurality of winding units 921. Each winding unit 921 is arranged on a respective board 911. A conducting path 922 is arranged on the bridge 912 and connected between two winding units 921. As such, the flexible base plate 91 may be folded to stack the boards 911 together, forming a multiple-layered winding structure of a motor. This simplifies the assembly procedure of the motor and increases the number of turns of the windings. Such a motor winding structure 9 may be seen in Taiwan Patent No. 1422123. The motor winding structure 9 may be arranged in any motor. The winding units 921 may be electrified to drive a rotor of the motor to rotate.
The winding assembly 92 of the motor winding structure 9 has similar problems as the winding assembly 82 of the motor 8. Specifically, in addition to the conducting path 922 connected between two adjacent winding units 921, it is also required to form a conducting hole on each board 911 in order to electrically connect the winding units 921 of the boards 911 together. Thus, the winding units 921 of the boards 911 can form the required serial or parallel connection structures or the combination thereof. More specifically, the winding unit 921 on each of the boards 911 may comprise a plurality of coils 921a each having a center “C” and two ends. Each coil 921a is arranged on the board 911 and extends in a clockwise or countclockwise manner. One of the two ends of the coil 921a is adjacent to the center “C,” and another end of the coil 921a is away from the center “C.” Since the coil 921a and the conducting path 922 are formed on the board 911 by layout, the conducting path 922 is unable to extend across the coil 921a to electrically connect to the end of the coil 921a adjacent to the center “C” (innermost part of the coil 921a). In this regard, the conducting path 922 can only be connected to the end of the coil 921a away from the center “C” (outermost part of the coil 921a). In light of the defect, it is required to form a conducting hole that extends through the board 911 at the center “C” of the coil 921a. Then, a conducting element such as a copper post, a conducting wire or a conducting layer is disposed in the conducting hole, such that after the flexible base plate 91 is folded, the innermost parts of the coils 921a can be connected to each other via the conducting element.
However, arrangement of the conducting hole and the conducting element increases the manufacturing cost and structural complexity of the motor winding structure 9. In addition, as compared with the single board 821 of the motor 8, the motor winding structure 9 includes plural boards 911. In this regard, after the flexible base plate 91 is folded, short circuit can occur between the winding units 921 of the adjacent boards 911 since electricity can be conducted at both sides of the board 911 via the conducting element inside the conducting hole. Thus, an insulation treatment has to be provided between the adjacent boards 911 (such as the arrangement of an insulating layer between the adjacent boards 911). However, the insulation treatment makes the production of the motor winding structure 9 inconvenient and may increase the thickness of the motor winding structure 9.
In light of this, it is necessary to provide a novel motor winding structure free of the above problems of the conventional motor winding assembly 82 and the winding structure 9 caused by the arrangement of the conducting holes on the boards 821 and 911, such as high cost, complex structure and inconvenient production procedure.